Views: 147 Author: Site Editor Publish Time: 2025-02-10 Origin: Site
Based on the operation data and energy-saving diagnosis report of XX Co., Ltd.’s stirring equipment, this renovation plan covers 280 motors with a total installed power of 6160 kW. The average annual operating time of the equipment is 7000 hours, and the average load rate is 73%. The industrial electricity cost is calculated at 0.8 yuan per kWh. Through the IE5 ultra-efficient synchronous reluctance motor system renovation, the expected energy-saving benefits are as follows:
The annual power consumption of the original system = rated power of a single motor × load rate × number of equipment × annual operating hours =22 kW×0.73×280×7000 = 31.47 million KWH
According to the power saving performance of synchronous magnetic reluctance motor system under similar working conditions, the estimated total power saving rate is 20%. Annual electricity saving = annual electricity consumption of the original system × electricity saving rate =3147 million degrees x 0.20 = 629 million degrees
Annual electricity saving = annual electricity saving × electricity price = 6.29 million KWH × 0.8 yuan/KWH = 5.03 million yuan Note: The above calculation is based on theoretical model and historical data, and the actual power saving rate needs to be compared through the measurement after transformation.
（2）Return on investment analysis
Investment cost accounting:
The single system is 60,000 yuan per set (the system includes motor, reducer, stirring and driver) Total investment = total number of sets × unit price =280×6 = 16.8 million yuan The investment recovery cycle is shown in the table below: (the evaluation error of electricity saving is ±5%)
Energy saving rate | 15% | Standard 20% | 25% |
Annual electricity saving (10,000 KWH) | 597.6 | 629 | 660.3 |
Annual electricity saving (ten thousand yuan) | 478.1 | 503 | 528.2 |
Investment payback period (years) | 3.5 | 3.3 | 3.1 |
Note: The error range of power saving rate is based on the fluctuation of equipment operating conditions and load rate change. The investment recovery cycle does not take into account policy subsidies and tax incentives. If subsidy income is included, the recovery cycle will be further shortened.
（3） Environmental benefit
Annual standard coal saving:
According to the "Standard Coal Coefficient for Power Conversion" released by the National Energy Administration, the energy consumption conversion coefficient for industrial electricity is: 1 degree of industrial electricity is about 0.296 kg of standard coal Based on the annual electricity saving of 6.29 million KWH after the transformation, the standard coal saving can be calculated as follows: Annual standard coal saving = 6.29 million KWH × 0.296 kg/KWH = 1,853 tons
Annual CO₂ reduction:
According to the standard of China Energy Statistical Yearbook, burning 1 ton of standard coal will emit about 2.7 tons of CO₂, so the annual emission reduction of CO₂ is calculated as follows: Annual emission reduction of CO₂ =1853 tons of standard coal × 2.7 tons of CO₂/ton of standard coal =5003 tons
Environmental benefit analogy, in order to more intuitively show environmental benefits, the reduction amount is converted into equivalent tree planting amount:
According to the United Nations Environment Programme, one tree absorbs an average of 18kg CO₂ per year. The equivalent tree planting amount is calculated as follows: quivalent tree planting amount =5003 tons CO₂ ×1000÷18 kg/tree ≈ 278,000 trees
2. Project Overview
This energy-saving technology transformation will be implemented on the premise of ensuring that the new system meets the technical indicators of the original system, the stable and normal operation of the equipment, the production process requirements and the stable operation of the enterprises mechanical and electrical equipment, with the core goal of energy saving and carbon reduction. A total of 280 stirring equipment units were installed in this energy-saving renovation, with a total installed power of 6,160 kilowatts.
photo of the scene:
Starting current: 280~400A The on-site operating current of a single unit is about 31A, and the load rate is about 73%
3. Energy saving technology and principle
（1）Energy saving motor: IE5 ultra high efficiency synchronous magnetic reluctance motor system
Permanent magnet assisted synchronous magnetic reluctance motor (PM a-Syn.RM) combines the advantages of permanent magnet synchronous motor and synchronous magnetic reluctance motor, with high energy efficiency, high reliability, environmental protection, small size and other advantages. It is suitable for industrial energy saving field and various machinery equipment supporting drive field, with broad market prospects. Jiangsu Huima Technology Co., Ltd.’s permanent magnet-assisted synchronous reluctance motor product has been included in the "National Industrial and Information Technology Sector Energy Saving and Carbon Reduction Technology Equipment Recommendation Catalog (2024 Edition)," and it is the only brand of reluctance motors listed in this catalog. Notably, in the detailed introduction to the catalog, Huima Technology permanent magnet-assisted synchronous reluctance motor product boasts an efficiency rating superior to Class 1 efficiency.
Principle of energy saving:
The synchronous magnetic reluctance motor has no slip, no loss of rotor, higher efficiency and wider high efficiency range.
（2）Energy-saving agitator
Based on the full process simulation technology of computational fluid dynamics (CFD), this scheme realizes the energy-saving design of agitator through the following systematic methods.
CFD simulation technology path:
▲ Demand analysis: Combine the process parameters (Reynolds number, Froude number) and material properties (viscosity, density, non-Newtonianity) to clarify the mixing efficiency, shear strength and energy consumption constraints.
▲ Parametric geometry modeling: NURBS surface is used to build high precision three-dimensional model of propeller, and dynamic optimization of key parameters such as blade inclination angle and number of blades is supported.
▲ Multi-physical field meshing: the hybrid mesh strategy (boundary layer encryption + polyhedron core mesh) is applied to ensure the balance between wall flow resolution (y+<5) and computational efficiency.
▲ Boundary condition setting: define inlet velocity profile (turbulent intensity ≤5%), outlet static pressure boundary and wall no slip condition to simulate real working conditions.
▲ Turbulent model selection: SST k-ω model is used to accurately capture the flow separation phenomenon in high shear region, and LES large vortex simulation is combined with LES to analyze the evolution of macroscopic vortex structure.
▲ Multiphase flow coupling analysis: VOF (Volume of Fluid) method is used to simulate the dynamic of gas-liquid interface, and DEM (discrete element method) is used to track the distribution of solid particles.
▲ Rotational domain modeling: Based on MRF (multiple reference frames) and slip grid technology, dynamic rotation of agitator and bidirectional coupling solution of flow field are realized.
▲ Power quantification: calculate the power quasi-number by torque integration method, optimize the blade shape to reduce the dimensionless energy consumption index.
Energy saving blade core advantages:
Technical dimension | Optimize the effect | quantitative index |
Energy efficiency improved | The turbulent kinetic energy dissipation of the flow field is reduced by 30%-40% Energy consumption per unit of output will fall by 18-25% | The power quasi number Np is reduced to 0.35-0.45 |
Mixed quality enhancement | Macro mixing time is reduced by 20% Microscopic mixing uniformity (coefficient of variation CV)<3% | The mixed efficiency index (Mixing Index) is greater than or equal to 0.92 |
Mechanical reliability optimization | The stress concentration coefficient of the blade (SCF) is less than 1.5 Safety margin of critical speed is greater than 15% | The amplitude of vibration is reduced by 40% The bearing life is extended to 50,000 hours |
Process adaptability expansion | Supports full range processing from Newtonian fluid (μ=1-10^4 cP) to shear dilute fluid The replacement time of the blade module is less than 2h | The viscosity adaptability range was extended to 10^6 mPa·s |
Environmentally friendly | Operating noise ≤ 72 dB (A) The heat recovery efficiency is greater than or equal to 65% | Compliant with ISO 3744 noise emission standards |
Safety redundant design | Failure mode coverage based on FEMA analysis is greater than 95% Emergency shutdown response time <0.5s | SIL 2 safety level certification |
4. Electricity saving rate measurement and analysis
（1）Electricity saving rate measurement method:
On the same equipment and under the same working conditions, the data collected by the electricity meter recognized by both parties shall be counted first for the original asynchronous motor and then for the synchronous magnetic resistance motor system.
The power consumption P old (kW/h) of a process flow in the original asynchronous motor operation, and the power consumption P new (kW/h) of the same process flow in the new synchronous reluctance motor system after installation and commissioning, where n is the total number of modified motors.
The energy saving rate of a single process is η = ((P old-P new) / P old) × 100%
Total energy saving rate η=(η1+η 2+……+η n)/n
According to the field collection and analysis of the operating status of the current motor, combined with the efficiency status of our companys energy-saving motor, the test of the power saving rate of our companys energy-saving motor by various testing institutions, and the feedback of some users use of energy-saving motor in recent years, the following points are analyzed.
（2）Energy saving estimate of motor system:
1. The original site uses the three-phase asynchronous motor of the YE2 series. If the motor is produced according to the national standard, its energy efficiency grade is IE2 or IE3. Compared with our companys GB18613-2020 first-class energy efficiency IE5 ultra-efficient synchronous magnetic reluctance motor system, the rated efficiency is increased by 2.0%~4.2%.
2. In actual operation, the original motor is often not in the rated working range, and the average load is about 50%-90%. At this time, the actual operating efficiency of the original motor is low, while the IE5 ultra-high efficiency synchronous magnetic reluctance motor system is in the high efficiency range in the load range of 20%-120%. Under this motor load, the efficiency of the synchronous magnetic reluctance motor system is 5% higher than that of the original motor.
（3）Energy saving estimate of mixing system:
Equipment modification part: reducer + motor + frame + stirring shaft blades.
Increase torque: gear reducer + motor 30KW1500 turn. Torque 2254.N.M.
electronic control:
Move forward and backward.
Multi-speed control:
First gear: start at about 0.5HZ, 5 minutes;
Second tier: 1HZ, 5 minutes;
Third tier: 5HZ, 5 minutes;
Fourth tier: 10HZ, 5 minutes;
Fifth tier: 20HZ, 5 minutes;
6th grade: 30HZ, 5 minutes;
7th tier: 35HZ, 5 minutes;
8th tier: 43HZ-50HZ, 20 minutes.
(Preliminary macro mixing, gradual micro mixing)
The weight ratio of uniform suspension is calculated as 1.3, the stirring grade is more than 10, the overall flow rate is 0.45, the circulation volume is 0.95m³/S, and the torque is 2136N.M linear velocity is 6.28-7.17.
Process part: The blade form is a lower pressure tube anchor frame with one layer of sawtooth slurry, which achieves the best cutting function. Through simulation calculation, it can grind the particle fineness of 1 micron for about 60 hours.
Actual shaft power: 13.22KW left and right. Frame diameter 800*H900*70*ZK800*100.
Running current: 32.6A. Speed 120r/min.
Estimation of paddle energy saving
The total power consumption P old of a process flow of the original motor = the power of the original motor × the load rate of the original motor × the total hours of the process flow
＝22×73%×72
＝1156kW
The total power consumption Pnew of the new system process is Pnew = actual shaft power × total hours of process
＝13.22×60
＝793kW
Estimated power saving of new process:
1-P new / P old = 1-793/1156 = 31.4%
In conclusion, the total power saving rate of this stirring system can reach more than 20%.
Note: The above is theoretical calculation, and the actual energy saving rate is based on the actual measurement data of the actual transformation.
